The market for active antennas with distributed radio chains in mobile telephony systems is very immature with only a small number of commercial products. Most active antenna arrays till now are related to testbeds.
One of the properties an active antenna array is desired to have is flexibility to adjust port characteristics based on needs. One example of flexibility is the ability to adjust beamwidths within a wide angular interval and of course to steer the beam in different directions. It is also desired to use the available power resource in an efficient manner.
Creating beams with beamwidths (in radians) approximately equal to one over the linear size of an antenna in wavelengths is known for a skilled person in the art using phase taper only and conventional beamforming, i.e. acting on one single polarization, as illustrated in connection with FIGS. 1 and 2. However, in many cases, creating wider beams are very difficult and sometimes even impossible with this conventional technique, using the power resource efficiently, as illustrated in connection with FIG. 3.